Good morning:

Thanks everybody for sharing your thoughts and practices regarding ID and listing of Northwestern Crows.? I got a wide variety of responses in addition to several requests for a summarization.

The general consensus is?that (at least in Western WA) true identification is not completely "field diagnosable".? Evidently WOS did a presentation on local corvids a few years back that suggested the mtDNA of our crow populations is highly variable -- the populations have intermixed to the point where even the AMCR is distinct from its counterparts east of the Cascades.? It would seem that historically the NOCR was indigenous to our coastal areas but as land was cleared, AMCR expanded its range west and largely swamped the NOCR gene pool.? One might think of this as somewhat analogous to our "Olympic Gull", where theres not really a clear separation between Glaucous-winged, Glaucous/Western, and Western Gulls -- especially since the data suggests that Alaskan crows tend to be more purely NOCR (genetically speaking, that is).

A few of you commented on my ebird remarks:?Please note that "American/NW Crow" means either/or as opposed to hybrid (something along the lines of "corvid spp.").? Upon closer examination of the ebird common species list, this does seem to be consistent with such possibilities as "Greater/Lesser Scaup" and "Common/Barrows Goldeneye" (again, obviously not?hybrids).

I also appreciated reading how you handle counting and listing.? Some of you dont count NW Crow at all, and some of you only count NW crow when you are in certain counties or areas (eg San Juan county == NOCR and everywhere else == AMCR).? A few responses challenged me to pay closer attention to possible subtle behavioral or?biological differences. One long time corviphile gave a great suggestion that crows foraging below the high tide line are more likely to be NOCR.

For me personally, I think I'm going to adopt the system of counting the San Juan county crows as NOCR and the rest of them as AMCR.? I like this approach for several reasons.? First,?when I'm birding the San Juans, it?should serve as a nice reminder to be on the lookout for unusual crow behavior.? Hopefully over time my observational skills will develop to the point that I can key into some of the more subtle differences.? And if that doesnt happen, maybe by then the scientists will have decided to merge the two species :-)

I hope you all have a warm and happy holiday, and a?bird-filled new year.?

Jon

-----Original Message-----
>From: Jon Leland <jon_leland at yahoo.com>
>Sent: Dec 21, 2009 4:04 PM
>To: tweeters at u.washington.edu
>Subject: [Tweeters] NW vs AM Crow
>
>Hi all:
>
>For those you listers, I am curious how you handle?ID and tracking for?American vs Northwestern Crow.? The resources I have consulted suggest that it is impossible to tell the difference other than range.? Do you just count it as NW Crow when youre on the Pacific Coast and AM crow the rest of the time?? I use eBird to track my sightings, and am a little amused that they even offer "American/NW Crow hybrid" as a common species.?
>
>Regards
>Jon Leland
>Seattle WA
>
>